Why can't I print to console after try block in Java?

Question

I have the following code in an Android application:

public static HttpResponse dbPost(String handlerUrl, List<NameValuePair> postData) {

    HttpClient httpclient = new DefaultHttpClient();
    String postUrl = constants.postUrl(); 
    HttpPost httppost = new HttpPost(postUrl);
    HttpResponse response = null;
    System.out.print("Catch 0");

    try {
        httppost.setEntity(new UrlEncodedFormEntity(postData));
        response = httpclient.execute(httppost);
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    System.out.print("Catch 1");

    return response;

}

I have a button that calls this block. If I press the button, the console will print "Catch 0" (but NOT "Catch 1"). If I press the button again (same instance), the console will print "Catch1Catch0". What's the problem?

I'm a bit new to Java so bear with me.

Answer 1

You need to call flush since you're using print .

System.out.print("Catch 1");
System.out.flush();

The default behavior of PrintStream is to only flush when a newline is written. (This behavior is documented in write(int) .)

If you used printLn instead of print , the stream would flush automatically. Without that, you need to explicitly flush the output stream.

Answer 2

您使用的是print而不是println 。